Method of effecting electric connection

ABSTRACT

Method for effecting electrical connection by electrical welding, according to which at least the portion of the connection to be welded to a part is in the form of two substantially parallel strips which are preferably close to each other and wherein each of the two electrodes of the welding apparatus is applied, during welding, respectively to one of said strips.

May 14, 1974 H. DENIS 3,810,790

METHOD 0F EFFECTING ELECTRIC CONNECTION Filed Feb.4 17, 1972 2 Sheets-Sheet 1 'la I' IN, C. nl h "Nh Hi" F|G2 y FIGC 17 15 Y m I 15 y l if FIG-4 @We/ Kx SI/ V H. DENIS IETHOD OF EFFECTING ELECTRIC CONNECTION May 14,v 1914 2 Sheets-#Sheet 2 Filed Feb. 1'?, 1972 FIG'. 5

United States Patent O .3,810,790 METHOD OF EFFECTING ELECTRIC CONNECTION j Henri Denis, Saint-Brce-sous-Foret, France, assignor to Saft-Societe des Accumulateurs, Fixes et de 'II-action Filed Feb. 17, 1972, Ser. No. 227,071 Claims priority, application France, Feb. 19, -1971,..-

. rntctHonn /004 Us. cl. 13s- 134 P z crains ABSTRACT or THE DISCLOSURE Method for effecting electrical connection by' electrical welding, according to which at least the portion of the connection to be welded to a part is in the form of two substantially paralled strips which are preferably close to each other and wherein each of the two electrodes` of the welding apparatus is applied, during welding, respectively to one of said strips.

BRIEF SUMMARY oF INVNT'ION end of the strip against a'suitable metal part ofthe' generator and by making the two electrodes of the welding apparatus bear on the said end of the strip.

Applicant has observed that in such event -theiweld effected was not always a good-quality weld; more particularly, that quality varies as a function of the relative thicknesses of the strip -to be welded and of thespport receiving it. This is due to the fact that a part of the weld current generated by the welding apparatus, flowing only -through thel thickness ofthe strip as a straylcurrent is not used for welding. l E' It is therefore, desirable for implementing-'this method that the thickness of the metal portionof the generator onto which the strip is welded be; greater than ther thickness of the said strip. i l 'i In order to avoid that interference or strayfcurrentf-fiow of the weld current only inside the strip' to .be=`welded, the weld could lbe effected by applying one welding electrode onto the strip to be welded and the other `ontofthemetal electrodes of the welding apparatus being applied, during welding, respectively on one of said strips.

:The existence of discontinuity between the portions of the. connection means on which the two welding electrodes bear has the effect of avoiding the existence of a detrimentalinterference or stray current, and thus enables good welds to be obtained.

' According to a particular embodiment, the said connection means comprises two distinct strips or blades arice .ranged parallel to each other without touching.

l According to another embodiment, and with the aim during the welding operation of ensuring more easily the relative positioning of the t-wo blades or strips, the said connection means takes the form of two substantially parallelmetalstrips, connected together by a common central portion remote from the locations at which welding is to-.be effected.

Other objects and features of the invention will become apparent from the following detailed description and the accompanying drawing, in which:

FIG. l is a top view of two cylindrical generators electrically connected according to the present invention by two parallel blades;

i FIGS. 2, 3 and 4 show respectively two electric weld methods according to prior art, mentioned in the preceding text and the method according to the invention; FIG. 5 is analogous to FIG. l, with a connection means formed by -t-wo blades connected by a common central portion.

DETAILED DESCRIPTION In FIG. l, the references 1 and 2 designate two cylindri cal electrochemical generators, for example, accumulators :or storage cells. In the example shown, these accumulators must be electrically connected together in series by connecting the metallic bottom 3 of the generator 1 with the opposite polarity metal cap 4 of the generator 2.

' The connection means used is in the form of two metallic strips or blades 5 and 6, each comprised, for exarnple','of -a'nickelsteel band, `arranged substantially parallel to and at a slightdistance from eachother, and'which are welded by applying the two electrodes of the welding apparatusrespectively to the adjacent ends, that is, at 7 and 8, and at 9 and 10, producing effectivewelds respectively at `7 land 8 and at 9 and 10. Y

" The advantages resulting from practicingl the method according t the invention appear clearly by reference to FIGS. 2,3 and 4.

part of the generator, in the proximity of the regin'of pletely through the first weld point'. This is a great disadvantage, for the use of high currents makes it com pulsory to use connecting strips having a" great width aplurality of weld points. y l "f The present invention, more particularly, enables oveicoming of these disadvantages.

It has for its object a method for effecting' electrical connection by electric welding, characterized iii' that at least the portion of the connection v"means to b'ewelded to a part is inthe shape of two strips which aresultistantial 'In these tgures, the reference 18 designates the metal portion of the generator onto which the connection means In the case of FIGS. 2 and 3, this connection means is in the form of a single strip 11,' whereas in the'case of FIG. 4, which corresponds to the practiceof the method according'to the invention, the .portion of the connection means to be welded comprises two parallel strips 12 and 13.

The arrows 14 and `15 symbolize the two electrodes of the welding apparatus.A

The current actually used and servingfor welding is designated by the arrow 16. v The arrow 17 in FIG. 2 designates the interference or stray current which is generated in the strip 11 onV application of the welding electrodes. It does not exist'in the case either of'FIG. 3 or 4. Nevertheless, in the case of FIG. 3, the part 18 undergoes an undesirable alteration at the point onto which the welding electrode 15 is applied'. 'l

1y parallel and preferably close together;'eachlof'thetwo .The method according to the Ainvention as illustrated in FIGS.y 1 and 4 enables excellent welds to be made even when'tleth'ickness of the part 18 is 'smaller than that of 'tlie"c'nr'i`ectiori` means, the respective thicknesses of these elements being, for example 0.2 and 0.5 mm., contrary 3 to the result obtained by utilizing the method according to FIG. 2.

The invention applies also to the case where only the portion of the connection means to be welded is in the form of two strips or blades, these two strips then being connected together by a common part, as shown in FIG. 5. In that example, the elements already described and shown in FIG. l bear the same references. The connection means 20 used is in the form of two metal strips 21 and 22 arranged substantially parallel and relatively close to each other and connected together by a common central portion 23. They are welded by applying the two electrodes of the welding apparatus to two adjacent ends, namely at 7 and 8 and at 9 and 10.

The advantages set forth previously as regards FIGS. 1 and 4 subsist despite the existence of the portion 23 electrically connecting the parts 21 and 22 of the connection means. Indeed, the interference or stray current symbolized by the arrow 24 which could be set up, will be negligible due to the distance it has to travel, which provides a sufficiently high resistance, respectively between two adjacent ends 7 and 8, or 9 and 10.

On the other hand, an extra advantage is apparent: the ease with which the connection means is positioned and held in place during welding.

Such connection means are more particularly used for providing current outputs. v

The method according to the invention is applicable equally as well, whether the connection means are substantially plane or curved.

Thus, according to the invention, it is possible to con nect accumulators of the disk type electrically together, by means of connection means in the form of two parallel strips curved and welded at their ends onto the said accumulators.

It should also be mentioned that, since the connection means being welded to the generator comprises two strips or blades this constitutes a safety factor due to the fact that if one strip becomes unwelded, the second strip still remains welded.

Lastly, it should be observed that the method according to the invention can easily be implemented for industrial purposes.

The present invention also has for its object an electrochemical generator provided with at least one connection means such as described and applied by the method of this invention. i

It is to be understood that variation in detail within the scope of the appended claims are possible and are contemplated. There is no intention, therefore, of limitation to the exact disclosure hereinabove presented.

What is claimed is:

1. An electrochemical battery comprising at least two electrochemical generators, output terminals for each generator, and connection means for electrically connecting one terminal of one generator to one terminal of the other generator, said connecting means comprising two substantially parallel strips closely disposed relative to each other and both welded to said one terminal of said rstnamed generator and also to said one terminal of said other generator.

2. An electrochemical battery according to claim 1, said strips being joined together in a region remote from the regions where they are welded to -said generators.

References Cited UNITED STATES PATENTS 3,427,202 2/1969 Wilke 136-175 3,615,867 10/1971 Cich et al. 136-175 1,651,726 12/1927 Osterman 136-128 FOREIGN PATENTS 157,097 10/ 1921 Great Britain 136-128 DONALD L. WALTON, Primary Examiner U.S. Cl. X.R. 2,19-117 

